no csl on jdk17 builds

[floriangantner]

Describe the bug
On jdk17 build no csl can be generated because the used citeproc dependecy is old.

jdk11 builds mention some warning on startup like: NashornEngine is deprecated

To Reproduce
Steps to reproduce the behavior:

1. build dspace server webapp with jdk17
2. start dspace server webapp
3. trigger some export of some publication as csl, e.g. in chicago style
4. no csl is generated and some error is logged

Expected behavior
We expect the csl to be generated.

Related work
https://github.com/4Science/DSpace/blob/e69f96c19984b87dc80e0803044bae289a8bf11f/dspace-api/pom.xml#L851C16-L851C16
There are some newer versions of citeproc which are compatible with jdk17. See PR.
As some general workaround the nashorn-core dependency can be added to jdk17 builds so citeproc 1.0.1 is stll working.

[corrad82-4s]

hello @floriangantner , as anticipated during our DSpace-CRIS 7 working group call, this is the commit who introduced the possibility of using an external service as CSL generator: 73fe8c9 . To use an external service, we deployed this project https://github.com/zotero/citeproc-js-server on a web server, then set property csl.web-service.url with the url of the service.

[floriangantner]

superseeded by PR #483